ES2703284T3 - Removable reciprocal union of two strut sections of a strut of variable formwork in length - Google Patents

Description

DESCRIPTION

Removable reciprocal union of two strut sections of a strut of variable formwork in length

The present invention relates in general to telescopic struts variable in length, as they are used, for example, in the construction as support or shoring of concrete shuttering elements. The present invention relates to a hook in G, according to the preamble of claim 1, for the reciprocal detachable connection of two strut sections of such a telescopic shuttering strut. Furthermore, the invention relates to a telescopic shuttering strut according to claim 8, the strut sections of which can be joined together so that they can be disassembled with the aid of a G-hook according to the invention.

The telescopic struts, as they are used in the construction sector as support or shoring of concrete shuttering elements, usually have an outer tube and a telescopic inner tube that can be moved therein. For the reciprocal detachable connection of the two tubes, a so-called G-hook with a circular cross-section normally serves, which extends through the through-holes formed in the two tubes and aligned with one another. In this case, the shape of the hook in G is normally selected in such a way that the hook in G can be fixed in a telescopic strut so that it can not be lost, which is done by means of a stirrup of the hook in G, which wraps the strut. In this case, the G hooks of this type are normally formed as a unitary component, or as a single piece, from a round steel by deformation thereof. Since up to 4 t of load or even more must be supported for each strut, the area of force transmission between the two tubes and, in particular, the G-hooks, must be very carefully dimensioned, since, by means of these , the total load of the inner tube is transmitted to the outer tube of the strut.

In the case of this dimensioning, the stresses of the wall of the hole along the through holes of the two tubes are frequently a determining calculation criterion, which leads to that, in general, the diameter of the hook in G must dimension larger than this would be necessary for the transverse load capacity. Since, due to a non-negligible clearance between the inner tube and the outer tube, the G-hook is subjected to flexion, in addition the calculation of the G-hook in terms of bending can also be determinant, which in turn it leads to the diameter of the hook in G being selected larger to reach a moment of resistance as large as possible, than what this would be necessary for the transversal force removal. The hook in G also normally presents throughout its entire length the same cross section, although this large cross section is only necessary in the area of the diameter of the outer tube. Since the G-hooks of the conventional telescopic prongs are generally oversized in terms of their transverse force loading capacity, whereby an unnecessary weight is caused and unnecessary costs are generated, the invention is based on the mission of indicating at least one embodiment with which the unnecessary weight and costs associated with this can be reduced.

GB 1148656 A discloses a hook in G according to the preamble of claim 1.

According to a first aspect of the present invention, to solve this task a G hook is therefore provided for the reciprocal detachable connection of two strut sections of a telescopic shuttering strut, which has the features of claim 1.

The G hook according to the invention includes a bolt, which serves for the reciprocal joining of the two strut sections, and a stirrup, by means of which the bolt can be secured to the strut so that it can not be lost. According to the invention, it is now foreseen that, in the case of the bolt and the stirrup, they are two different pieces, which are present at first as separate components, or separate, which, in the context of the manufacture of the hook in G, are joined together until they become a composite component, namely the hook in G according to the invention. In particular, during the manufacture of the G-hook, the bolt and the stirrup are connected to each other in a torsionally rigid manner, which can be preferably carried out by means of a press fit connection, a positively joined connection, a welded and / or welded joint.

Since the bolt and the stirrup are therefore present as separate parts at first, it is possible to dimension the bolt only in a very special way as regards the determining calculation criteria. Accordingly, according to the invention, it is provided that the bolt has a force application section with a curved surface at least in regions and a force removal section diametrically opposed to the force application section, the surface of which does not have any or at least one curvature, which is smaller than the curvature of the curved surface of the force application section.

By means of the preferred torsionally rigid connection between the bolt and the stirrup of the G-hook according to the invention, it is possible to configure the stirrup as an open hook, without the anti-loss protection thereby suffering, which is effected by means of the stirrup. In this way, in particular due to the torsionally rigid connection between the bolt and the stirrup, the bolt can not be rotated in relation to the stirrup after the bolt has been pulled out of the through holes of a formwork strut. Therefore, in this unlocked state of the G-hook the distance between the free end of the bolt and the free end of the stirrup is still maintained, which it is dimensioned in such a way that the G hook can not be extracted from the respective strut to which it is secured.

Whenever it is mentioned here that the force application section has a curved surface at least in zones, this must also be understood as a fundamentally flat force application section, which is only rounded or bevelled in the passage areas towards the longitudinal sides of the bolt. In this way, for example, a square steel can also be used as a bolt for the G hook according to the invention, which is only rounded along its edges in order to avoid unwanted stress spikes in the area of the adjoining components, in particular of the walls of the bore of the strut pipes. By means of the force application section curved at least in zones, it can therefore be ensured that the forces to be transmitted through the bolt are distributed over a large area, whereby the stresses of the bore wall can be maintained lowers of the desired shape in the area of the through holes of the inner tube of a telescopic shuttering strut.

On the other hand, the configuration of the force removal section as a flat or only minimally curved surface proves to be particularly advantageous when the forces that must be transmitted through the bolt have to be applied in a strut section not directly, but rather in a indirect, through a recess nut, as explained below more precisely. Since this recess nut also has a flat front side, on which the bolt force transmission section is placed, by means of the flat or only minimally curved surface of the force stripping section not only a reduction is achieved of the tensions between the bolt and the recess nut. Rather, by means of the flat or only minimally curved surface of the force removal section it is also ensured that the bolt can not be twisted, which, if not, could unintentionally cause a bending of the bolt. around his "weak axis." In other words, by means of the essentially flat configuration of the force removal section an anti-torsion or self-centering protection is achieved, by means of which it can be ensured that the bolt is always loaded in the desired direction.

The manufacture of the G-hook according to the invention from two separate separate parts - bolt and stirrup - thus proves to be particularly advantageous in that the bolt can be dimensioned and manufactured as a special profile in a very special way. with regard to the decisive calculation criteria such as, for example, bending capacity and / or transverse force load, as well as stresses of the hole wall, while the stirrup can be manufactured from a simple standard profile as a component more light, so that, ultimately, you can not only reduce weight, but, in particular, also costs. The manufacture of the G-hook according to the invention from two separate separate parts also proves to be advantageous, however, in that, due to the multitude of parts, the bolt and the stirrup can be manufactured from different materials, in particular steels of different qualities. Therefore, the bolt can be manufactured from a steel of quality S355, while for the stirrup a lower quality steel can be used, so that costs can be saved again.

In particular, for the first time a two-piece G-hook is thus created, the individual parts of which - bolt and stirrup - are connected to each other in a torsionally rigid manner, due to the fact that only the Bolt, which is responsible for the force removal between the strut sections of a strut of telescopic formwork, can be configured as a special solid profile, for example as a forged part, rolled profile or cast part, from a steel, e.g. For example, S355 quality, while for the stirrup, which only serves as an anti-loss protection, a simpler and more cost-effective standard profile can be used, the total weight of the G-hook and manufacturing costs can be kept low. in the way explained above. In addition, the stirrup of the hook in G according to the invention has, compared to conventional G-hooks, a smaller cross-sectional area, which has the consequence that the stirrup can be cold formed, whereas At its larger sectional surface, the stirrups of conventional G-hooks should generally be made hot. Due to cold forming, manufacturing costs can therefore be reduced further.

According to another aspect of the present invention, the task that is based on it is also solved by means of a telescopic shuttering strut with an outer tube and an inner tube that can be displaced therein, where, for reciprocal detachable connection of the two tubes, a G hook according to the invention is used, which extends through the through holes configured in the two tubes and aligned with each other.

In the following, advantageous embodiments of the invention are now reached; other advantageous embodiments can be deduced in addition to the dependent claims, from the description of the figures and the drawings.

The features explained below with reference to the G hook according to the invention, as well as to the formwork strut according to the invention, are also correspondingly valid for the object not explicitly referenced in each case. For example, the features explained with respect to the bolt according to the invention can be applied in a corresponding manner to the telescopic formwork strut, or to its hook in G.

According to the invention, the bolt has a first protruding free end and a fixed second end opposite the first end, in the area of which it is connected with the stirrup in such a way that the front surface of the bolt is exposed in its Second end as impact surface. In particular, in this case the force application section and the force removal section of the bolt may be joined to one another by means of a passage section, of which the stirrup preferably protrudes at right angles and, to Following this here, it extends in the direction of its free first end at least in zones parallel to the pin. Unlike in the case of conventional G-hooks, in which case the bolt becomes the one-piece stirrup, the G-hook bolt according to the invention therefore has a front surface defined at its second end, by means of which the pin can be nailed in the through holes of a shuttering strut, for example, using a hammer, beating with the hammer blows on the front surface in question of the pin.

In order to be able to connect the bolt and the yoke of the G-hook in accordance with the invention with simple means, according to another embodiment, it is provided that in the area of the second end of the bolt in the passage section a orifice, in which a second end of the stirrup is secured. Preferably, in this case, it is provided that the hole and the second abutment end are configured to be contoured in complementary fashion to each other in such a way that the second abutment end is secured by a forced connection and without the possibility of turning in the hole. In this case it is sufficient to secure the second stirrup end to the bolt, for example, with a welded point, so that the second stirrup end can not be pulled out of the hole formed in the bolt passage section. Likewise, it would be possible to minimally extend the second abutment end after it has been inserted into the hole in the passage section, in order to further generate a frictionally driven connection between the second abutment end and the bolt. By means of an extension of the second stirrup end outside the hole of the passage section, in addition to the generated friction force closure, it is guaranteed that the second stirrup end can not be extracted from this hole.

According to another embodiment, it is provided that the bolt has a cross-sectional configuration essentially U-shaped, C-shaped, similar to a beam in the form of a double T, O-shaped, tubular or oval. In the case of a U-shaped cross-section, the free ends of the "U" together form the force removal section and, therefore, the arc of the "U" forms the force application section of the bolt. . If, on the other hand, the bolt has a cross section fundamentally similar to a double T-shaped beam, the force application section is formed by means of one of the flanges of the double T with curved surface at least in zones , while the section of force removal is formed by means of the other flange, less or not curved, of the double T. In the case of a cross-section of C-shaped bolt, the section of application of force and the The force removal section is formed by means of diametrically opposite curvature sections from one to the other of the "C", wherein one of these curvature sections may, however, be flattened as a force removal section.

To create an insertion aid for the hook in G in the through holes of the respective strut, in which the hook is to be inserted in G, it is provided according to another embodiment that the pin is narrowed at least in zones similarly to a wedge in the direction of its first end protruding free.

Preferably, in this case it is provided that the bolt itself similar to a wedge has two plateau areas spaced apart from one another in the longitudinal direction of the bolt, in the area of which the bolt does not taper. In the case of this embodiment, the bolt, viewed from its end protruding free in the longitudinal direction, is formed by means of a first wedge section that is enlarged, a first plateau area then a second wedge section which is then expanded and a second plateau area below, wherein preferably the second wedge section is separated from the first plateau area by means of a step. The two plateau areas are in this case separated from one another by a measure, which corresponds approximately to the diameter of the inner tube of the respective formwork strut, so that, in the preparation state, the inner tube can rest with the walls of the hole of their holes through the two plateau areas. Since, unlike the wedge sections, the plateau areas of the bolt have a defined distance from the lower side of the bolt, on the one hand it is therefore guaranteed that the respective formwork strut, whose length is marked using a G hook in accordance with the invention, present a defined length that does not depend on how deep the pin itself has been nailed similar to a wedge inside the through holes of the strut. On the other hand, by means of the plateau areas, it is guaranteed that the bolt that narrows itself in a manner similar to a wedge can not be separated by vibrations under dynamic loads, which can act on the strut.

Furthermore, the wedge-shaped configuration of the bolt proves to be advantageous in the sense that, in this way, a so-called stripping of the strut head can be carried out in order to achieve a discharge of the strut. If, in particular, in the state of preparation of the respective strut the bolt is pulled out of the holes through the same again partially, this leads to the inner tube descends corresponding to the narrowing of the bolt, so that the Strut is unloaded and then can be disassembled more easily. Since, in theory, during the preparation process there is the possibility of driving the bolt so deep into the through holes of a strut that the inner tube does not rest in the desired manner on the two plateau areas, but only on the second enlarging wedge section, according to another embodiment it is provided that the second wedge section is separated from the first plateau area by half a step. In this case, this step serves in a certain sense as a stop, which comes into contact with the inner wall of the inner tube of the strut, whereby the pin is prevented from being keyed so deep into the through holes that the inner tube only rest on the second wedge section that is extended.

As can be deduced from the previous embodiments, the present invention is based on the knowledge that, in general, the conventional G hooks are oversized by zones, so, according to the invention, it is proposed to manufacture the hook in G from two separate pieces - bolt and stirrup -, which makes it possible to configure very specifically as a special profile only the bolt in order to be able to achieve the necessary moments of resistance, or to maintain the wall tensions of the hole allowed. However, in order that the permitted wall stresses of the hole can be effectively maintained, it is further provided that the through-holes of the inner tube are contoured in a manner complementary to the shell of the bolt at least along the area of the wall of the hole. , through which the transmission of force from the inner tube to the force application section of the bolt is performed, wherein, in the case of a bolt that tapers similarly to a wedge, the through holes of the tube interior have different height measurements. Thus, if, for example, the bolt has a C-shaped cross section geometry, it is provided that, in a manner analogous to the envelope of the C-profile of the bolt, the through-holes of the inner tube have an oval design, so that the forces can be transmitted from the inner tube distributed as widely as possible through the hole wall of the respective through hole to the bolt.

In order to be able to divert in the desired way through the bolt to the outer tube of a telescopic shuttering strut the loads caused in the bolt in this way, the load dismantling in the outer tube is carried out by means of the recess nut already previously mentioned, which can be displaced in the longitudinal direction of the strut in the area of two through holes aligned with each other of the outer tube, which are configured as two grooves that run in the longitudinal direction of the strut, by means of a external thread configured on the outer tube. In this case, the recess nut has a flat front side, on which the force removal section of the bolt of the G-hook rests in a flat manner, so that, in the event that the bolt has to be inclined to be tilted. around its longitudinal axis, a recoil force is generated, which brings the bolt back to its correct orientation, in which it is placed with its force removal section on the entire surface on the flat front side of the nut. rebate In this way not only a protection against torsion is achieved, but also a reduction in the stresses acting on the recess nut, whereby a hardening of the surface of the recess nut can be deducted. Therefore, it is possible to prevent the bolt of the hook in G from sinking into the flat front side of the recess nut, which, if not, could lead undesirably to the load nut being loaded. The recess can no longer be dismantled or only very difficult or, for the purpose of length adjustment, the strut can no longer be turned in the desired manner.

In the following, the invention is now described purely by way of example by exemplary embodiments with reference to the accompanying drawings, in which:

Fig. 1 shows a perspective representation of a G-hook according to the invention according to a first embodiment;

Fig. 2 shows another perspective representation of the hook in G of Fig.1;

Fig. 3 shows a side view of the hook in G of Figs. 1 and 2;

Fig. 4 shows an enlarged representation of detail "A" of Fig. 3;

Fig. 5 shows a sectional view along the cut lines B-B of Fig. 4;

Fig. 6 shows another cross-sectional shape for the bolt of a G-hook according to the invention;

Fig. 7 shows another form of cross section more for the bolt of a G-hook according to the invention;

Fig. 8 shows a perspective representation of a section of a shuttering strut according to the invention;

Fig. 9 shows a vertical section of the strut of Fig. 8;

Fig. 10 shows a view of the inner tube of the strut of Fig. 8 in the area of a through hole;

Fig. 11 shows a perspective representation of a G-hook according to the invention according to another embodiment;

Fig. 12 shows another perspective representation of the hook in G of Fig.11;

Fig. 13 shows a vertical section of a shuttering strut with the hook in G according to Figs. 11 and 12; Fig. 14 shows a view of the inner tube of the strut of Fig. 13 in the area of the through holes; Y

Fig. 15 shows detail "E" of Fig. 13 in an enlarged representation.

Next, it is now described first, with reference to Figs. 1 to 3, a first embodiment of a G-hook 10 according to the invention, which serves for the reciprocal detachable connection of two strut sections 110, 112 of a strut of telescopic formwork 100, as it is shown. more precisely described below with reference to Fig. 8. The hook in G 10 according to the invention is composed essentially of two separate separate pieces, in particular, of a pin 12, which serves for the reciprocal joining of the two strut sections, and a bracket 14, by means of which the bolt 12 can be secured to the formwork strut 100 in a manner that can not be lost, the stirrup 14 wrapping the formwork strut 100. In accordance with the invention , the two pieces - bolt 12 and abutment 14 -, of which the hook is made in G 10, are preferably joined to each other in a torsionally rigid manner, which can be achieved, for example, when the bracket is welded. with e The bolt 12. In the embodiment shown, however, the bolt 12 and the bracket 14 are joined to one another by forced connection and driven by friction, which is then reached even more precisely.

As can be seen in particular from the detail "A" of FIG. 3 shown in FIG. 4, the bolt 12 has, in the illustrated embodiment, a cross section substantially similar to a double T-shaped beam, wherein the The upper flange 16 has in its central area 19 a flat surface with infinitely small curvature, while the upper flange 16 is configured in its lateral areas 20 with respectively a curved surface, whose curvature can also be clearly greater than in the case of the shape of embodiment shown in Fig. 4, so that the cross section would be substantially symmetric with respect to the cut line BB. The upper flange 16 is connected by means of a core 21, or passage area 21, to the lower flange 18 of the bolt 12 similar to a double T-shaped beam, wherein the lower surface of the lower flange 18 is configured fundamentally flat and, therefore, also has an infinitely small curvature.

The flat surface of the lower flange 18 forms a force removal section 22 of the bolt 12, since, through it, the forces caused in the bolt 12 can be deflected evenly. The surface curved at least in regions of the upper flange 16, on the other hand, forms a force application section 24 of the bolt, by means of which the forces are caused from the strut to the bolt 12, whereby by means of the curved side areas 20 can achieve a stress distribution of the uniform hole wall.

Due to the configuration of the bolt 12 with a cross section fundamentally similar to a double T shaped beam, compared to a conventional G hook with circular cross section, it is possible to achieve, with less material consumption, the same or even better static cross-sectional values, whereby, at the end of the day, manufacturing costs can be reduced. In particular, the costs for the manufacture of the G-hook 10 according to the invention can be reduced, however, by treating in the case of the bolt 12 and in the case of the stirrup 14 of different parts, so that, for example, , the bracket 14 can be manufactured from a low quality single round steel, while the bolt 12 can be manufactured as a special profile of high quality steel with, for example, a cross section similar to a double T-shaped beam , as is the case in the embodiment represented referring to Figs. 1 to 5. In other words, the costs for the hook in G 10 according to the invention, due to the duality of parts thereof, can be reduced by configuring, for example, the bolt 12 as a relatively solid component with values of optimized static cross section, while for the stirrup 14 a less solid standard profile with lower static cross section values can be used. Accordingly, the cost advantages of the present invention could also be achieved in the case of an embodiment in which the bolt 12 is configured as a simple square profile with, if necessary, minimally rounded edges for, in this way, as in the case of the embodiment explained with reference to Figs. 1 to 5, to be able to achieve a voltage distribution of the hole wall as uniform as possible.

However, the manufacture of the G-hook 10 according to the invention from two separate separate components 12, 14 not only proves to be advantageous, however, because, due to the duality of the parts, the bolt 12 and the stirrup 14 can present different cross sections. Rather, due to the duality of the parts of the hook in G 10, the bolt 12 and the bracket 14 can be manufactured from different materials, in particular steels of different qualities, so that only the bolt 12 needs to be manufactured, for example, from a steel of the quality S355, while for the stirrup 14 a lower quality steel can be used, whereby the manufacturing costs can be reduced again. Furthermore, in comparison with conventional G-hooks, the bracket 14 of the G-hook 10 according to the invention has a smaller cross-sectional area, which has the consequence that the bracket 14 can be cold formed, whereas , due to their larger cross-sectional surfaces, the stirrups of conventional G hooks are due to General shape in hot. Due to cold forming, manufacturing costs can therefore be reduced further.

Another advantage of the G-hook 10 according to the invention arises, due to the placement of the bracket 14 as a separate component on the bolt 12, when the second end 28 of the bolt is exposed outward at the second end 28 of the bolt 12, or the front surface 40, opposite the first end 26 protruding free front and, therefore, can be used as impact surface, through which the bolt 12 can be nailed into the through holes of a strut formwork Thus, the bracket 14 is in particular placed laterally in the web 21, which joins the upper flange 16 which serves as a force application section 24 and the lower flange 18 serving as the force removal section 22. Due to the fact that the bracket 14 therefore protrudes essentially at right angles to the passage section 21, in order to extend therefrom in the direction of its free first end 30, the front surface 40 is therefore uncovered on the outside. second end 28 of the bolt 12, so that the bolt 12 can be driven through it with the help of a hammer in the through holes of a strut. Since the abutment 14 protrudes substantially at right angles to the passage section 21, the abutment 14 must only flex approximately 90 ° to extend therefrom in the direction of its free first end. Compared to conventional G-hooks, the bending radius can therefore be increased, so that even larger cross-sections of stirrup can be flexed by cold forming, whereby manufacturing costs can be kept low.

Precisely, the bracket 14 could be welded to the core 21 laterally in the area of the second end 28 of the bolt 12. However, in the represented embodiment it is provided that an orifice 34 is configured in the area of the second end 28 of the bolt 12. in the core 21, which houses the second end 32 of the stirrup 14. As can be better deduced from Figs. 5 and 9, in this case the orifice 34 has an oval design, through which the second end 32 of the abutment 14 previously formed is converted into an oval cross section, so that, due to the complementary contours of the Hole 34 and the second end 32 of the bracket 14, a torsionally rigid connection between the bolt 12 and the bracket 14 is already provided.

In order to prevent the stirrup 14 from being able to be removed from the hole 34, in the case of the embodiment shown referring to FIGS. 1 to 5, on the front side of the bracket 14 at the second end 32 a recess 36 is stamped, by means of which the second end 32 of the bracket 14 is enlarged, so that the bracket 14 is connected to the pin 12 of way that can not be lost. Instead of securing the bracket 14 in the hole 34 by means of the enlargement caused by means of the notch 36, it is also possible, however, to weld or solder the bracket 14 with some tin with the core 21, thereby it is also possible to prevent the stirrup 14 from being extracted from the hole 34.

Although the hook in G 10 represented with reference to Figs. 1 to 5 has a bolt 12 with a cross section essentially similar to a double T-shaped beam, the bolt 12 can also, however, have other cross-sectional shapes. For example, the bolt 12 can present, in the manner already explained above, a square cross section with slightly rounded or bevelled edges. According to another embodiment, it is provided that the bolt 12 has a substantially U-shaped cross section according to FIG. 6, in which the two free ends of the "U" are respectively flattened to form a force-removal section together 22, by means of which the forces caused in the bolt 12 can be deflected in a uniformly distributed manner. The surface section of the bolt 12 opposite the two free ends of the "U" forms, on the other hand, a force application section 24 with a curved surface, whereby a stress distribution can be achieved in the desired manner. uniform hole wall.

According to another embodiment, the G-hook 10 according to the invention can have a bolt 12 with a substantially C-shaped cross-sectional design, as is shown in FIG. 7. Again, it is envisaged again both a curved force application section 24 and a flattened force removal section 22, which are formed here by means of diametrically opposed "C" curvature sections.

With reference to Figs. 8 to 10, now describes a strut of telescopic formwork 100 according to the invention, which has an outer tube 112 and an inner tube 110 telescopic that can be moved therein. According to FIG. 9, the outer tube 112 is provided at its free end with an external thread 116 (not shown in FIG. 8 for reasons of clarity), in which a recess nut 114. is screwed. outer 112 has two through holes 113 opposite each other in the form of elongated slots, while inner tube 110 has at its free end several through holes 118 spaced apart from each other in the longitudinal direction of the strut, which are aligned with the longitudinal through holes 113 of the outer tube 112.

As can be deduced in particular from FIG. 9, the G-hook 10 extends with its bolt 12 through the through holes 113, 118 formed in the two tubes 110, 112 and aligned with each other, wherein the bolt 12 of the hook in G 10 presents here the cross-sectional configuration similar to a double T-shaped beam explained in particular with reference to Fig. 4. The loads from the inner tube 110 are therefore transmitted through the walls from the hole of the through holes 118 to the bolt 12 and, from there, through the recess nut 114, to the outer tube 112 of the strut 100. In order to keep the stresses of the wall of the hole as small as desired. Along the walls of the hole of the through holes 118, the through holes 118 of the inner tube 110 are contoured in a complementary manner to the shell of the bolt 12. The surface pressures between the recess nut 114 and the force stripping section 22 also they remain small, which is because it rests on the entire surface on the front side 115 of the recess nut 114.

Since the surface pressures between the recess nut 114 and the force stripping section 22 are therefore kept small, there is no danger that the pin 12 will sink into the recess nut 114, which, if not thus, it would have as a consequence that the recess nut 114 can not be rotated, or only very difficult, for the precision adjustment of the length of the telescopic shuttering strut 100 or, under load, can not be disassembled or only very difficult. In addition, due to its G-shaped design, the tendency of the G-hook 10 to rotate about the longitudinal axis of the bolt 12 is counteracted by the flat configuration of the force-removing section 22 of the bolt 12, acting the transverse forces acting on the bolt 12 in connection with the planar configuration of the force dismounting section 22 as a recoil force on the hook at G 10, which counteracts an undesired rotation thereof.

In the case that no recess nut 114 is provided for the precision adjustment of the length, and therefore, instead of the through holes 113 in the form of a groove in the outer tube 112 as in the inner tube 110, a plurality of through holes 113 disposed separately from each other are provided, these through holes 113 and / or also the through holes 118 in the inner tube 110 can have a complementary contour with respect to the contour of the respective pin 12. The contour of the respective through-hole 113, 118 must not, in this case, exactly correspond to the contour of the bolt 12, provided that this prevents an undesired bolt rotation. In this way, a torsional protection can also be achieved, so that, in this case, it would be possible to do without at least, for the benefit of a reduction in the stresses of the wall of the hole, a flat configuration of the force removal section 22, if no recess nut 114 is provided for the precision adjustment of the length, in which the bolt 12 could sink.

With reference to Figs. 11 and 12, now another embodiment of a G-hook 10 according to the invention is described, which differs from the first embodiment represented with reference to Figs. 1 to 5 fundamentally only in that the bolt 12 narrows at least in zones similar to a wedge in the direction of its first end 26 protruding free. Precisely, the bolt 12 can be narrowed continuously starting from its second end 28 to its first end 26; however, according to the embodiment shown in Figs. 11 and 12, it is provided that the wedge-shaped bolt 12 in its force application section 24 has two plateau areas 50, 52 separated from one another in the longitudinal direction of the bolt, in the area of which the 12 bolt does not narrow. The bolt 12 is therefore formed, viewed from its first end 26 protruding free in the longitudinal direction, by means of a first wedge section 54 that is enlarged, a first plateau area 50 then a second wedge section. 56 which is then expanded and a second plateau area 52 below, wherein in the illustrated embodiment the second wedge section 56 is separated from the first plateau area 50 by means of a step 58, which is provided in the force application section 24.

The wedge-shaped configuration of the bolt 12 proves to be advantageous in this case in the sense that, on the one hand, an insertion aid is created through this, which facilitates the insertion of the bolt 12 into the holes two strut-section crossings 110, 112. On the other hand, the wedge-shaped configuration of the bolt 12 facilitates stripping of a strut of telescopic shuttering 100, whose strut sections 110, 112 are joined to each other with assistance of such a wedge-shaped pin (see Fig. 13), a force being applied, for example, with a hammer blow on the front surface at the first end 26 of the bolt 12. Because of the hammer blow, the bolt 12 it is partially removed from the strut 100, which has as a consequence that the inner tube 110 descends correspondingly to the narrowing of the bolt 12, whereby the strut 100 is discharged and then can be disassembled more easily.

So that, in the case of a G 10 hook with a wedge-shaped bolt 12, the forces are not transmitted to the bolt 12 from the inner tube 110 only through the wall of the hole in one of the through holes 118, in FIG. this embodiment provides that the through holes 118 of the inner tube 110 are raised differently (see Figs 13 and 14). In this case, the heights of the two through holes 118 should be selected as such. so that the inner tube 110 rests along the areas of the hole wall of its two through holes 118 over the entire surface on the force application section 24 of the wedge-shaped pin 12.

For, due to the dynamic forces, which can act on the strut 100, to avoid a separation by vibrations of the wedge-shaped tapers 12, it is advantageous to configure them, in the manner already explained above, with the two plateau areas 50, 52, in the area of which the pin 12 does not narrow. In this case, the plateau areas 50, 52 are separated from one another by a measure, which corresponds approximately to the tube diameter of the inner tube 110, so that it can rest on the two plateau areas 50, 52 Furthermore, the configuration of the bolt 12 with the two plateau areas 50, 52 proves to be advantageous in the sense that the length of the telescopic strut 100 does not depend on how deep the wedge-shaped pin 12 is keyed into the through holes. 118. It should only be ensured that the wedge-shaped bolt 12 is driven so deep into the through holes 118 that the inner tube 18 rests on the plateau areas 50, 52, whereby all similar struts, which are provided with such a wedge-shaped pin 12, they can be set to the same extraction length.

For, during the nailing of the wedge-shaped bolt 12 in the through hole 18 of the inner tube 110, there is no danger that the bolt 12 will be keyed both in the strut 100 that the second wedge section 56 reaches the area of the orifice corresponding passage 118 in the inner tube 110, between the second wedge section 56 and the first plateau area 50 is formed the aforementioned step 58, which, in this case according to FIG. 15, makes contact in the inner wall of the inner tube 110 and, therefore, prevents a too deep nailing of the bolt 12 in the strut 100. A too deep nailing of this type of the bolt 12 in the strut 100 is likewise prevented by means of the bracket 14, since it protrudes , preferably at right angles, of the bolt 12 in the manner previously explained. This leads to the bracket 14, according to Fig. 13, coming into contact with the outer tube 114, whereby too deep nailing of the bolt 12 in the strut 100 is prevented, so that the configuration of the step 58 between the second wedge section 56 and the first plateau area 50.

List of reference symbols

10 hook in G

12 bolt

14 stirrup

16 top flange

18 lower flange

19 central area of 16

20 side areas of 16

21 soul, or area of passage between 16 and 18

22 force dismantling section

24 force application section

26 first end, or free, of 12

28 second end of 12

30 first end, or free, of 14

32 second end of 14

34 hole

36 notch

38 enlargement

40 front surface

50 first plateau area

52 second plateau area

54 first wedge section

second step wedge section

strut of telescopic shuttering interior pipe

outer tube

elongated through hole in 112 recess nut

front side of 114

external thread in 112

through hole in 110

Claims (10)

1. Hook in G (10) for the reciprocal detachable connection of two strut sections (110, 112) of a strut of telescopic formwork (100), with a bolt (12), which serves for the reciprocal union of the two strut sections (110, 112), and a stirrup (14), by means of which the bolt (12) can be secured in the formwork strut (100) so that it can not be lost, where, in the case of the bolt (12) and the stirrup (14) are treated in two different parts, which are made from different materials and are joined to each other, and wherein the bolt (12) and the stirrup (14) are joined together to become a composite component, and wherein the bolt (12) has a force application section (24) with curved surface (20) at less by zones characterized in that the bolt (12) has a force removal section (22) opposite diametrically to the force application section (24), the surface of which does not have any or at least one curvature, which is smaller than the curvature of the surface (20) of the force application section (24), and that the bolt (12) has a first end (26) protruding free and a second end (28) opposite the first end (26), in the area of which it is connected with the stirrup (14) in such a way that the front surface of the bolt (12) is exposed at its second end (28) as the impact surface. 2. Hook in G according to claim 1 characterized in that the bolt (12) and the stirrup (14) are manufactured from steels of different qualities. 3. Hook in G according to at least one of the preceding claims characterized by that the force application section (24) and the force removal section (22) of the bolt (12) are joined to each other by means of a passage section (21), of which the stirrup (14) it projects preferably at a right angle and then extends in the direction of its free first end (30) at least in regions parallel to the bolt (12). 4. Hook in G according to claim 3 characterized by that in the area of the second end (28) of the bolt (12) is formed in its passage section (21) an orifice (34), in which a second end (32) of the stirrup (14) is secured, wherein the the hole (34) and the second end of the stirrup (32) are preferably contoured in a complementary manner to each other in such a way that the second end of the stirrup (32) is secured in positive connection in the hole (34). 5. Hook in G according to at least one of the preceding claims characterized by that the bolt (12) has a cross section fundamentally similar to a double T-shaped beam, wherein the force application section (24) is formed by means of a flange (16) with at least a curved surface (20) by zones and the force removal section (22) is formed by means of the other flange (18) of the double T, or that the bolt (12) has a U-shaped cross section, wherein the free ends of "U" respectively form a section of force removal (22), or that the bolt (12) has a C-shaped cross section, where the force application section (24) and the force removal section (22) are formed by diametrically opposed "C" curvature sections the one to the other, or that the bolt (12) has a tubular-shaped cross-section, in particular with an O-shape, or a complete oval cross-section. 6. Hook in G according to at least one of the preceding claims characterized by that the bolt (12) narrows in a manner similar to a wedge at least in regions in the direction of its first end (26) protruding free, wherein the bolt (12) preferably has two plateau areas (50, 52) separated from one another in the longitudinal direction of the bolt, in the area of which the bolt (12) does not taper. 7. Hook in G according to at least one of the preceding claims characterized by that the bolt (12), viewed from its end (26) protruding free in the longitudinal direction, is formed by means of a first wedge section (54) that is enlarged, a first plateau area (50) then a second wedge section (56) which is then expanded and a second plateau area (52) next, wherein preferably the second wedge section (56) is separated from the first plateau area (50) by means of a step (58). 8. Telescopic shuttering strut (100) with an outer tube (112) and an inner tube (110) that can be displaced therein, where, for the reciprocal detachable connection of the two tubes (110, 112), it is provided a hook in G (10), which extends through through holes (113, 118) configured in the two tubes (110, 112) and aligned with each other, characterized by that the hook in G (10) is configured according to one of claims 1 to 7. 9. Formwork strut according to claim 8 characterized by that the through holes (118) of the inner tube (110) are contoured, at least along the area of the wall of the hole, through which the force removal is performed from the inner tube (110) to the application of force (24), in a manner complementary to the envelope of the bolt (12), wherein, respectively, two through holes (118) of the inner tube (110) aligned with each other are raised differently in the case of a bolt (12) that tapers similarly to a wedge. 10. Telescopic strut according to claim 8 or 9 characterized by that the through holes (113) of the outer tube (112) aligned with each other are configured as two slots (113) running in the longitudinal direction of the strut, in the area of which a recess nut (114) can be formed. moving in the longitudinal direction of the strut by means of an external thread (116) configured in the outer tube (112), wherein the recess nut (114) has a flat front side (115), on which it rests flatly the force removal section (22) of the bolt (12) of the hook in G (10).